Engagement and retention: measuring breadth and depth of participant use of an online intervention.
Couper MP, Alexander GL, Zhang N, Little RJ, Maddy N, Nowak MA, McClure JB, Calvi JJ, Rolnick SJ, Stopponi MA, Cole Johnson C.
Couper MP, et al. Among authors: zhang n.
J Med Internet Res. 2010 Nov 18;12(4):e52. doi: 10.2196/jmir.1430.
J Med Internet Res. 2010.
PMID: 21087922
Free PMC article.
Clinical Trial.